Plant for the production of pressed sheets

ABSTRACT

IN A PLANT FOR THE PRODUCTION OF PRESSED SHEETS, WHEREIN A MULTIPLICITY OF CRUDE MATS ARE FED SIMULTANEOUSLY BETWEEN THE PLANTENS OF A PRESS FROM A MULTILEVEL CHARGING STATION DISPOSED ALONGSIDE THE PRESS BY A FEEDING ARM DISPLACEABLE TOWARD THE PRESS, AN ARRANGEMENT WHEREBY THE FEEDING ARM CARRIES A PLURALITY OF FINGERS SELECTIVELY DISPLACEABLE TO ENTRAIN SPACER BLOCKS INTO THE PRESS WHEN IT IS DESIRED TO CHANGE THE THICKNESS OF THE STEEL PRODUCED BY THE PLANT.

Jan. 5, 1971 K, M m, $351,944

PLANT FOR THE PRODUCTION OF PRESSED SHEETS Filed May 20, 1968 I v 4 Sheets-Sheet 1 Karl MUI/er 1 N VENTOR.

Attorney 4 Sheets-Sheet? K. MULLER PLANT FOR THE PRODUCTION OF PRESLSED SHEETS Jan. 5, 1971 Filed May 20, 1968 Karl MUI/er I N VEN TOR.

w W Attorney Jan. 5, 1971 K. MULLER 3,551,944

PLANT FOR THE PRODUCTION OF PRESSED SHEETS Fil'ed May 20, 1968 4 Sheets-Sheet 5 INVENTORI Karl MUI/er Attorney Jan. 5, 1971 K. MULLER 3,551,944

PLANT FOR THE PRODUCTION OF PRESSED SHEETS Filed May 20, less 4 Sheets-Sheet 4.

Ross A Attorney United States Patent (3 3,551,944 PLANT FOR THE PRODUCTION OF PRESSED SHEETS Karl Miiller, Krefeld-St. Tonis, Germany, assignor to G. Siempelkamp & Co., Krefeld, Rhineland, Germany, a corporation of Germany Filed May 20, 1968, Ser. No. 730,452 Claims priority, application Germany, May 20, 1967, S 109,951 Int. Cl. B29c 3/04 U.S. Cl. 184 Claims ABSTRACT OF THE DISCLOSURE In a plant for the production of pressed sheets, wherein a multiplicity of crude mats are fed simultaneously between the plantens of a press from a multilevel charging station disposed alongside the press by a feeding arm dis placeable toward the press, an arrangement whereby the feeding arm carries a plurality of fingers selectively displaceable to entrain spacer blocks into the press when it is desired to change the thickness of the sheet produced by the plant.

My present invention relates to apparatus for the production of pressed sheets and, more particularly, to a plant for the production of pressed board using multilevel charging and discharging stations flanking a multilevel press.

In the commonly assigned U.S. Pat. 3,379,124 and 3,379,322 issued Apr. 23, 1968 and copending application Ser. No. 534,231 filed Mar. 14, 1966 (U.S. Pat. 3,389,- 652), there are described various arrangements for the charging of multiplaten presses with crude mats, stacks or other layer-like accumulations of materials for compression into coherent sheets or pressed board. It has become the widespread practice in the art to produce pressed board, generally known generically as fiberboard, in multiplaten presses in which a plurality of levels are formed by heated platens of a press, each platen cooperating with the next higher platen to compact loosely coherent or prepressed fibrous mats or crude layers into coherent sheets. Thus, hardboard, fiberboard or like relatively rigid and more or less dense sheets can be produced from loosely coherent fibrous mats of a comminuted material (e.g. wood fiber, sawdust or the like), using natural binders found in the material, or thermally ac tivatable binders added thereto. In the aforementioned patents, systems have been described for simultaneously charging the platens of a press using a charging station disposed adjacent the latter and provided with a multiplicity of levels each aligned with a respective platen of the press. In general terms, the press may be of the type described in the commonly assigned U.S. Pats. 3,050,777 and 3,209,405. The platen structures may be heated as disclosed in the commonly owned U.S. Pat. 3,241,189. Multilevel charging stations have been described in the commonly owned Pats. 3,050,200 and 3,077,271.

It has been found to be advantageous (see U.S. Pat. 3,379,322) to simultaneously displace the crude mats of loosely coherent materials onto the platens of a multilevel or multiplanten press with the aid of a charging arm or feed arm which is advanced in the direction of the press and carries and/or pushes the crude layers onto the respective platens with the aid of pusher bodies carried by this arm. The arm may be suspended from a carriage above the charging station and a multilevel press and can be operative to feed the crude layers to the latter with or without charging trays or may be formed with conveyer platens operable upon the return stroke of the feed arm to deposit the crude mats upon the platens of the press.

In my U.S. Pat. 3,206,800, I have also observed that it is advantageous to provide a plant using a multiplanten press with means for spacing the platens apart, such means including spacer magazines alongside the charging rack for depositing spacer bars upon the latter for advance on respective charging trays or concurrently with such charging trays into the press; the magazines are vertically displaceable to align their discharge openingss with the levels of the charging rack, while receiving magazines may be provided on the discharge side to pick up the spacer bars upon their passage from the press.

It has been found that systems of the latter type are not always as effective as desirable when it is necessary to change the thickness of the sheets produced after the formation of sheets of a different size for one or more cycles.

Accordingly, it is the principal object of the present invention to provide a plant for the production of pressed board to permit of the selective change of board thickness in a convenient, simple and eflicient manner.

This object and others which will become apparent hereinafter are attainable, in accordance with the present invention, with a system using a charging arm for simultaneously advancing a plurality of crude mats onto the respective platens of a multilevel press, wherein the arm is provided with a plurality of fingers each associated with a respective level of the charging station and adapted to be jointly shifted between an inoperative position and an operative position. In the latter position, the fingers, advanced with the charging arm of the feed means, entrain respective spacer bars, guided in respective interfitting longitudinally extending formations of each charging level into the press which may be provided with corresponding interfitting formations, thereby pushing the previous spacer elements from the press.

According to this invention, the spacer elements are arrayed at the respective levels of the charging station for one or more press-charging operations with the fingers in their inoperative position and the charging arm is reciprocable to advance the crude layers into the press in which the prior spacer elements remain for one or more cycles of pressed-board production to yield sheets of a thickness corresponding to the spacer elements retained in the press. When it is desired to change the thickness of the pressed board, the fingers are shifted jointly into their operative position and engage the spacer elements at the charging station to entrain them into the press at the next press-charging stroke of the charging arm.

According to a feature of this invention, the entrainment fingers extend radially from respective shafts having horizontal axes and are journaled for rotation upon the charging arm, the fingers being disposed at an end of each shaft remote from its cantilevered support close to its opposite end. The shaft extends generally in the direction of advance of the charging arm so that the fingers project transversely to this direction. At the charging arm, I provide a common actuating bar linkage via levers or the like with the respective shaft and vertically shiftable by an actuating mechanism (e.g. crank) to shift the entrainment fingers between their operative and inoperative positions.

According to still another feature of this invention, the spacer elements are provided with longitudinally extending grooves in which extending longitudinal ridges of the charging levels are received to guide the spacer elements onto the press which is generally provided with longitudinal formations aligned with or identical or corresponding to those of the charging levels. In this system, the groove or recess of the spacer element may be laterally open to allow the spacer elements to be positioned at the respective charging level for magazines as described in my U.S. Pat. 3,206,800. The converse relationship,

whereby the spacer elements are provided with longitudinally extending ribs, and the charging levels and pressed platens are formed with complementary longitudinally extending grooves, may also be used.

The system of the present invention allows rapid change of the thickness of the pressed board and, therefore, the density thereof, accommodates spacer elements which may be inserted by hand or automatically (e.g. via the magazines described above) and provides a convenient method for withholding change of spacers when such change is not desired.

The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a fragmentary elevational view of a pressed charging system using a multilevel charging station and a charging arm as described generally in U.S. Pat. 3,379,322;

FIG. 2 is a view taken in the direction of arrow II of FIG. 1 showing the attachment of the control means for the entrainment fingers to the feed or charging arm;

FIG. 3 is an elevational view illustrating the system of the present invention, and in which the charging arm and charging arrangement of the type disclosed in U.S. Pat. 5

3,379,322 although it will be understood that substantially any charging structure using an arm for jointly advancing a multiplicity of crude layers into the multiplaten press may be employed. Typical of such other structures is that described in my U.S. Pat. 3,206,800. Referring first to FIGS. 1 and 2 of the drawing, it will be seen that a system for feeding crude sheets jointly to the platens of a multiplaten press may comprise a charging rack 3 whose levels 3a receive charging plates 3b whose ridges 3c guide the abutment surfaces 3d as will be apparent hereinafter. The charging station comprises, in addition to the support levels or platforms 3a of the rack, a stacked array of the charging plates 3b which are slidable in the charging station in the direction of arrow A and carry the crude mat M. The charging station is, of

course, disposed adjacent a multiplaten press 1 (FIG. 3)

as will be described in greater detail hereinafter. The number of charging plates 3b corresponds to the number of stages 3a of the charging station 3 and to the number of levels 2 of the multiplaten press 1. As described in k U.S. Pat. 3,379,322, the charging station 3 is so constructed that the support frame and the individual stages 3a are provided with a central gap (in a vertical plane) through which the depending arm 3e can pass to advance the mat M into the press and return the plates 3b to the charging platforms 3a. The arm 3e may extend in a vertical median plane of the charging station 3 and the multiplaten press 1 while having a carriage 31 whose rollers 3g, received within the carriage 3f, suspend the arm 3e from a rail assembly represented at 3h (FIG. 2) and shown in dot-dash lines as lying in a vertical median plane through the assembly of FIG. 1. When the system of US. Pat. 3,379,322 for controlling the charging arm is employed, the arm 3e need not be provided with any drive means but may be freely movable on the rail assembly 3h for displacement by a further arm 3i disposed rearwardly of arm 3e with respect to the direction of advance (arrow A) of the mat M into the press. The arm 31' likewise depends from a carriage 3] whose rollers 3k are supported on the rail 3h. The arm 3i can be driven by a motor as represented at 3m or can merely. be-manually displaced as required. The arm 3i forms a lost-motion linkage with an I-beam 3n carried by the arm 3e so that the arm 3i engages the latter only after a limited advance defined by the abutment 3p. Movement of the arm 3i to the left (arrow A in FIG. 1) will permit it to pass through its plate Without entrainment of the plates 317 or the arm 3e until this arm 3i engages the abutment 3p. Thereafter, the arms 3e and 31 will move simultaneously in the direction of arrow A. Upon movement of the arm 3i to the right, however, it will be retracted through the range of play until it engages the rearmost flange of the I-bearn 3n to retract the plates 3b. The arm 31 is formed with the abutment slides or heads 3d mentioned earlier for aligning the rearmost surfaces of the mat M. The means for charging the plates 3b with the mat M is fully described in U.S. Pats. 3,379,124 and 3,379,322 as well as in the copending application Ser. No. 534,231 so that further discussion of such means is not necessary here. However, the arm 32 is formed also with a transverse support beam 3: which carries the actuating means for the entrainment fingers as will be apparent from FIGS. 3-5.

In FIGS. 3-5, I have shown somewhat diagrammatically the actuating means for selectively controlling the entrainment of spacer elements into the press, it being understood that the structure of the press-charging arm has been omitted here to facilitate an understanding of the present improvement.

Thus, the charging rack 3 is disposed adjacent a multiplaten press 1 and is provided, alongside each of the charging stages 3a, with an outwardly turned angle-iron support 7a, two such supports being provided on the opposite longitudinal sides of the support platforms 3a although only one has been illustrated in FIG. 5. The horizontal portions of the angle irons 7a are formed with longitudinally extending guide ribs 7, i.e. guide means, for the elongated spacer blocks 6 which are recessed or channeled at 9 to feed the ribs 7 and thereby preclude lateral shifting of the guide element 6- as they are advanced into the press 1 (arrow 15 in FIG. 3). The depending charging arm 3e carries the transverse beam or traverse 3q mentioned earlier (FIG. 5) forming outriggers from which vertical supports 10 depend (FIGS. 3 and 5).

The means for advancing the spacer bar 6- intothe press 1 comprises a rack finger 8 carried by each of a number of horizontal shafts 10 via respective bosses 8a keyed to these shafts. Each of the shafts is journaled in a block 10a on an angle-iron rail 10b cantilevered from the traverse 3q on an upright 100, the angle iron 10b running along rollers 10d mounted on the bolts 10e connecting the angle iron 7a with the platforms 3a of the charging rack. At the extremity of each shaft 10 remote from the transverse or radial finger 8, I prove an actuating lever 11 which, via its boss 11a, is keyed to the shaft 10 and is provided with a slotted extremity 11b slidably receiving an actuating pin 11c carried by the vertical actuating bar 12. The actuating bar 12 is shiftable in the direction of arrow 13 (FIGS. 3 and 4) by a crank assembly including a shaft 12a journaled in the bearing block 12b on the traverse 3q and adapted to rotate the levers 12c extending radially from the bases 12d on opposite sides of the charging rack (see FIGS. 2 and 5 Each of the levers 1120 is connected flexibly to the vertical bars 12 by pivoting links 12e. At one side of the assembly (FIG. 3), the shaft 12a is provided with a lever 12 which may be displaced manually or via a motor against the load of a counterweight 12g. The magazine for loading the bars 3 onto the angle irons 7a of the platform 3a is represented at 6a and may be of the type described and illustrated in my Pat. No. 3,206,800.

During normal press operation, the charging arm 3e, 3i can be advanced in the direction of the press (arrow 15) together with the rack or frame upright 10c (FIGS. 35 while the finger 8 is in its solid-line position (FIG. 5) corresponding to the extreme upper position of the bar 12, the extreme counterclockwise position of the shaft 12a (FIG. 4) and the extreme clockwise position of the shaft .10 (FIG. 5). The fingers 8 will thus clear the spacer bar 6, and the spacer bar 6, previously inserted between the platen 2 of the press 1, will remain in place for successive press cycles in which the spacer bar 6' determines the thickness of the sheets. The previously used spacer bars 6" have already been pushed into the discharging station 5 which may correspond to the discharge means described and illustrated in -U.S. Pat. No. 3,206,800.

When it is desired to change sheet thickness, the shaft 12a is rotated in the clockwise sense (FIG. 4) to lower the bars 12, which are guided in lateral projection 3g of the traverse 3g, to swing the levers 11 of all of the shafts in the counterclockwise sense (arrow in FIG. 5) and thereby move the finger 8 into its dot-dash position illustrated in FIG. 5. Forward movement of the arms 3e, 31' and the support form will cause fingers 8 to entrain the spacer bars 6 in the longitudinal direction (arrow 15 in FIG. 3) and convey these bars into the press while simultaneously pushing the bars 6' onto the discharge rack 5. Thereafter, the shaft 12a may be swung in the counterclockwise sense (FIG. 4) to restore the system to its solid line position as illustrated in FIGS. 3-5. The platen 2 of the press may be provided with formations 2. aligned with and of a configuration corresponding to the formation 7 to form guides for the bars 6, 6', 6 as previously indicated.

The invention described and illustrated is believed to admit of many modifications within the ability of persons skilled in the art, all such modifications being considered within the spirit and scope of the appended claims.

I claim:

1. In a plant for the production of pressed board wherein a multiplicity of mats are stacked upon respective platforms of a multilevel charging station flanking a multiplaten press having a number of platens corresponding to the number of platforms of the charging station and are simultaneously advanced onto the respective platens of the press by a press-charging arm reciprocable toward and away from the press in presscharging direction and in arm-retracting direction, respectively, and wherein respective spacer bars are disposed along each platform and are longiutdinally shiftable into the press and onto respective platens thereof to define the thickness to which the mats are compressed between the platens of the press, the improvement which comprises entraining means carried by said arm and shiftable therewith in said press-charging direction, said entraining means having an operative position engageable with said bars at said platforms for simultaneously advancing said bars from said platform onto the corresponding press platens, and an inoperative position wherein said entraining means clears said bars at said platforms upon movement of said arm in said press-charging direction.

2. The improvement defined in claim 1 wherein said entraining means includes a respective finger associated with each of the bars at each of said platforms, and means defining a pivotal axis for each of said fingers extending in said press-charging direction, said fingers being disposed radially of the respective axis and being swingable thereabout between said positions.

3. The improvement defined in claim 2 wherein said means defining said pivotal axis includes a respective shaft carrying each of said fingers at a forward end thereof and rotatably mounted on said arm, and actuating means carried by said arm for jointly rotating said shafts.

4. The improvement defined in claim 3 wherein said actuating means includes a vertically shiftable bar carried by said arm, and respective actuating levers mounted upon each of said shafts at the other end thereof engaging said bar for joint swinging movement upon linear vertical reciprocation of said bar.

'5. The improvement defined in claim 4 wherein each of said levers has a slotted free extremity'and said bar is provided 'with respective pins slidably received in said slots.

6. The improvement defined in claim 1 wherein each of said platforms and the respective bar are provided with complementary guide formations longitudinally guiding said bars into said press.

7. The improvement defined in claim 6 wherein said guide formations include longitudinally extending ridges formed on said platforms, said bars being formed with longitudinally extending recesses receiving said ridges.

8. The improvement defined in claim 6 wherein said actuating means further comprises a horizontal shaft journaled on said arm and extending transversely of said direction, a further lever carried by said horizontal shaft, and link means connecting said further lever with said bar.

9. The improvement defined in claim 8, further comprising a counterweight connected with said horizontal shaft for at least partially retaining said bar in a position thereof corresponding to the inoperative position of said fingers.

10. The improvement defined in claim 1 wherein said platens are provided with guide formations corresponding to and longitudinally aligned with the corresponding formations of the respective platforms.

References Cited UNITED STATES PATENTS 3,206,800 9/1965 Miiller 184 3,353,690 11/1967 Nagaoka 2.1416.6 3,379,322. 4/196 8 Bruder 214-166 J. SPENCER OVERHOLSER, Primary Examiner B. D. TOBOR, Assistant Examiner US. Cl. XJR. 18-16; 21416.6 

